Push rod



Ap 1 963 R. A. MOONEY, JR 3,086,507

I IPusH ROD Filed Sept. 26, 1961 ROBERT AMO'ONEV INVEN/Iggg ATTORNEYSUnited States Patent 3,086,507 PUSH ROI) Robert A. Mooney, J12, OrchardLake, Mich., assignor to Ford Motor Company, Dearborn, Mich., acorporation of Delaware Filed Sept. 26, 1961, Ser. No. 140,760 11Claims. (Cl. 123-90) This invention relates to the valve gear. Inparticular the invention relates to a push rod stabilizing means for aninternal combustion engine embodying a valve gear arrangement whereineach rocker arm is pivotally mounted upon its own support.

In overhead valve engines it is common practice to support the rockerarm upon a rocker arm shaft which extends in a direction parallel to thelongitudinal axis of the internal combustion engine. It is also commonin overhead valve engines to provide an individual support for eachrocker arm. In the latter instance the rocker arm is laterally unstableand must be stabilized in some manner.

A common method of push rod stabilization is to provide a slot in thecylinder head which restricts the lateral motion of the push rod.Designs of this type however require a polished and hardened push rodbody to resist abrasion. Push rods of this type also add to the totalengine noise.

Another method of push rod stabilization is by means of a bracket whichis secured to the underside of the valve cover and extends downwardlyinto the interior of] the rocker arm itself. This construction is shownin U.S. Letters Patent 2,818,843 issued in the name of M. H. Frank onJanuary 7, 1958.

Still a further method of stabilization is the type which stabilizes apair of adjacent push rods by means of a plate that is secured to thetop of the engine frame. A construction of this type is disclosed in US.Letters Patent 2,963,012 issued in the name of Kolbe on December 6,1960.

In an embodiment of this invention it is proposed to stabilize the pushrod by guide means in the (form of a stamped push rod guide mountedadjacent to the cylinder head. A bearing made from a moldable plastic ofa thermoplastic or ther-mosetting type such as nylon, Teflon, acetal orphenolic resin is mounted in an opening in the push rod guide. The pushrod extends through the bearing and is stabilized in a directionparallel to the longitudinal axis of the internal combustion engine.Movement of the push rod in a direction perpendicular to thelongitudinal axis of the internal combustion engine, however, ispenrnitted. In this construction a minimum ofi lubricant is required,the noise level is greatly diminished, and a push rod structure whichrequires a minimum amount of finish work is used.

It is also possible to embody the push rod guide in an oil baflle andtrough construction. The hearing may either move in the slot in theguide or be installed in a substantially stationary position with thepush rod moving relative to the bearing.

Other objects and advantages of this invention will become more apparentwhen considered in connection with the accompanying drawings, wherein:

FIGURE 1 is a transverse sectional view taken through an over-head valveengine that embodies the invention, and

FIGURE 2 is a perspective view of a combined oil battle and push rodguide shown in FIGURE 1, and

FIGURE 3 is an enlarged fragmentary perspective view partly in sectionof the push rod guide and bearing means embodied in the structure shownin FIGURE 1,

and i FIGURE 4 is an enlarged fragmentary perspective view of a portionof a push rod guide that embodies an alternate form of bearing.

Referring now to the drawings and in particular FIG- URE 1, a portion ofthe internal combustion engine valve gear (overhead type) is indicatedat 10. The rocker arm is indicated generally at 11 and comprises alongitudinally extending web 12 and upstanding sides 13 (one of which isshown) integrally connected to the web 12. A hemispherical bearingportion 14 is provided in the web 12 integral therewith and on the sideof the web 12 to the upstanding sides 13. A longitudinal extending slot16 is provided in the hemispherical bearing portion 14.

A hemispherical bearing 17 is nested in the bearing portion 14. Bearing17 is provided with a central bore 18 that is substantially axiallyaligned with the slot 16. Stud 19 (threaded at the outer end) extendsthrough the bore 18 in the bearing 17, slot 16 of the rocker arm, and ispress fitted or anchored in any well known manner in the rocker armsupport boss 21 of the cylinder head 22. An adjustable nut 20 securesthe rocker arm 11 and bearing '17 upon the stud 19.

Oscillatory movement is imparted to the rocker arm 11 through push rod24. Push rod 24 may be tubular in construction and may have an aperturedball tip end portion 26 that is received by a concave push rod engagingend 27 located in the rocker arm web 12. The bore of the push rod 24 isconveniently open to a source ofi pressurized lubricant such as thehydraulic tappet. An opening 28 in the concave push rod engaging end '27allows the flow of lubricant out of the push rod 24 onto the web 12. Thelubricant may then work its Way between the bearing 17 and the bearingportion 14 of the rocker arm 11.

Push rod 24 may extend through an enlarged opening 23 in the cylinderhead 22. Depending upon the type of internal combustion engineconstruction, the opening 23 may be in the cylinder head, the intakemanifold, the cylinder block, or in a combination of two or more of theaforementioned elements. Opening 23 may be sufliciently large so as topermit the easy removal of the push rod 24 (and even the hydraulictappet which is not shown) and the passing of the lubricant from thevalve gear portion of the engine to the engine sump. In any event, thepush rod 24 does not touch or engage any portion of the cylinder head,or part or parts comprising the opening 23.

Rocker arm 11 is also provided with a poppet valve engaging end 29 thatengages the end portion 31 of the poppet valve 32. Poppet valve 32 islaterally stabilized by the valve guide 33 of the cylinder head 22.Spring retaining means for poppet valve 32 comprises the usual springretainer 34, locking means 36 that engage the poppet valve stem, andvalve spring 37.

It is, of course, necessary to stabilize the rocker arm 11 in thedirection that is parallel to the longitudinal axis of. the engine. Thisis accomplished by the push rod stabilizing means indicated generally at41. Push rod stabilizing means 41 is shown in cross section in FIGURE 1,in perspective in FIGURE 2, and fragmentarily in FIGURE 3.

Push rod stabilizing means 41 comprises a stamped push rod guide 42.that is provided with a plurality of apertures 43 through which eachstud 19 extends. Push rod guide 42 is further provided with a pluralityof open end slots 44 located near the end of each of the push rods 42adjacent the valve spring 37. Slots 44 are Wider than the diameter ofthe push rod 24.

One or more oil troughs 47 may be provided in the push rod guide 42 fordirecting the oil from the valve gear to the opening 23. The attachmentof the push rod guide 42 to the cylinder head 22 may be made by springloaded nuts 43 which grip the stud 19.

To avoid metal-to-metal contact, a bearing 51 having 'a central bore 52and an annular groove 53 is inserted in each of the open end slots 44 sothat the sides of the slot 4 extend within the annular groove 53.Annular groove 53 may be made slightly smaller in diameter than thewidth of the open end slot 44 and larger in width than the thickness ofthe push rod guide 42. Central bore 52 may be figured dimensionally tosnugly fit the push rod 24. This structure is shown in enlarged detailin FIG- URE. 3.

Bearing 51 may be of a moldable plastic of either the thermoplastic orthermosetting type, particularly of the group having inherent lubricityand damping properties. Nylon is particularly adaptable to thisapplication. Phenolic resin, Teflon and acetal, among other plastics,are also suited for this application. In the structure disclosed inFIGURES l and 3, oscillatory movement by the push rod 24 results in thebearing 51 sliding in the open end slot 44.

In FIGURE 4, an alternate form of a moldable plastic bearing is shown. Ahorseshoe shaped bearing 54 is provided with a peripheral groove 56 thatallows the bearing 54 to be inserted snugly in the open end slot 44. Inthis arrangement the bearing 54 once inserted in the slot 44 is notintended to move. Push rod 24 simply rides inside the slot 57 of thebearing 54.

It is also possible to provide a push rod guide in which the bearingmaterial is attached, for example, by dipping.

It is to be understood, therefore, that the invention is not to belimited to the exact construction shown and described but that variouschanges and modifications may be made without departing from the spiritand scope of the invention as defined in the appended claims.

What I claim is:

1. An internal combustion engine comprising a rocker arm support, arocker arm pivoted upon said rocker arm support, said rocker arm havinga push rod engaging end and a poppet valve engaging end, a poppet valvehaving an end portion engaged by said poppet valve engaging end of saidrocker arm, a push rod having an end portion engaged by said push rodengaging end of said rocker arm, and push rod stabilizing means, saidpush rod stabilizing means comprising a longitudinal slot formed in acomponent of said engine, said push rod being reciprocally received insaid longitudinal slot and freely movable in a first direction relativeto said slot, and a plastic member interposed between said slot and saidpush rod for restricting motion of the push rod in a second directionwhile permitting free motion of said push rod in said first direction.

2. An internal combustion engine comprising a cylinder head, a rockerarm support adjacent to the cylinder head, a pivotally mounted rockerarm supported upon the rocker arm support, said rocker arm having a pushrod engaging end and a poppet valve engaging end, a laterally stablepoppet valve having an end portion engaging said poppet valve engagingend of the rocker arm, a push rod having an end portion engaging saidpush rod engaging end of the rocker arm and a push rod stabilizingmeans, said push rod stabilizing means comprising a moldable plasticmember located near the end of the push rod which engages the rocker armand being arranged to sharply restrict the motion of the push rod in adirection parallel to the longitudinal axis of the internal combustionengine, while permitting substantial movement in a directionperpendicular to the longitudinal axis of the internal combustionengine.

3. An internal combustion engine comprising a rocker arm support, arocker arm pivoted upon said rocker arm support, said rocker arm havinga push rod engaging end and a poppet valve engaging end, a poppet valvehaving an end portion engaged by said poppet valve engaging end of saidrocker arm, a push rod having an end portion engaged by said push rodengaging end of said rocker arm, and push rod stabilizing means, saidpush rod stabilizing means comprising an open ended longitudinal slotformed in a component of said engine, said push rod being reciprocallyreceived in said open ended longitudinal slot and freely movable in afirst direction relative to said slot, and a plastic member interposedbetween said slot and said push rod for restricting the motion of thepush rod in a second direction while permitting free motion of said pushrod in said first direction.

4. In an internal combustion engine comprising a cylinder head, a rockerarm support mounted upon said cylinder head, a pivotally mounted rockerarm supported upon the rocker arm support, said rocker arm having a pushrod engaging end and a poppet valve engaging end, a laterally stablepoppet valve having an end portion engaging said poppet valve engagingend of the rocker arm, a push rod having an end portion engaging saidpush rod engaging end of the rocker arm and push rod stabilizing means,said push rod stabilizing means comprising a push rod guide adjacent tothe cylinder head, said push rod guide having an open ended slot whoselongitudinal axis is transverse to the longitudinal axis of the internalcombustion engine, bearing means mounted in said slot, said bearingmeans being apertured to receive a portion of the push rod and laterallystabilize the push rod.

5. An internal combustion engine comprising a cylinder head, a pluralityof rocker arm supports mounted upon said cylinder head, a plurality ofpivotally mounted rocker arms, each of said rocker arms being supportedupon a rocker arm support, each of said rocker arms having a push rodengaging end and a poppet valve engaging end, and a plurality oflaterally stable poppet valves mounted in said cylinder head, eachpoppet valve having an end portion engaging the poppet valve engagingend of the rocker arm, a plurality of push rods, each of said push rodshaving an end portion engaging the push rod engaging end of a rocker armand push rod stabilizing means, said push rod stabilizing meanscomprising a push rod guide mounted upon said cylinder head, said pushrod guide having a plurality of open ended slots, each of said slotsbeing located near the end of the push rod that engages the rocker arm,the longitudinal axis of each of said open ended slots being transverseto the longitudinal axis of the internal combustion engine, moldableplastic bearing means mounted in each of said slots, each of saidbearing mean being apertured to receive a portion of a push rod andstabilize the push rod in a direction parallel to the longitudinal axisof the internal combustion engine, while permitting substantial movementin a direction perpendicular to the longitudinal axis of the internalcombustion engine.

6. An internal combustion engine comprising a cylinder head, a pluralityof rocker arm supports mounted upon said cylinder head, a plurality ofpivotally mounted rocker arms, each of said rocker arms being supportedupon a rocker arm support, each of said rocker arms having a push rodengaging end and a poppet valve engaging end, and a plurality oflaterally stable poppet valves mounted in said cylinder head, eachpoppet valve having an end portion engaging the poppet valve engagingend of the rocker arm, a plurality of push rods, each of said push rodhaving an end portion engaging the push rod engaging end of a rockerarm, and push rod stabilizing means, said push rod stabilizing meanscomprising a push rod guide mounted upon said cylinder head, said pushrod guide having a plurality of open ended slots, each of said slotsbeing located near the end of the push rod that engages the rocker arm,the longitudinal axis of said open ended slots being transverse to thelongitudinal axis of communicating with the internal combustion engine,moldable plastic bearing means mounted in each of said slots formovement along said slot, each of said bearing means being apertured toreceive a portion of a push rod and stabilize the push rod in adirection parallel to the longitudinal axis of the internal combustionengine, said bearing means being movable by said push rodin a directionperpendicular to the longitudinal axis of the internal combustion engm.

7. An internal combustion engine comprising a cylinder head, a pluralityof rocker arm supports mounted upon said cylinder head, a plurality ofpivotally mounted rocker arms. each of said rocker arms being supportedupon a rocker arm support, each of said rocker arms having a push rodengaging end and a poppet valve engaging end, and a plurality oflaterally stable poppet valves mounted in said cylinder head, eachpoppet valve having an end portion engaging the poppet valve engagingend of the rocker arm, a plurality of push rods, each of said push rodshaving an end portion engaging the push rod engaging end of a rocker armand push rod stabilizing means, said push rod stabilizing meanscomprising a push rod guide mounted upon said cylinder head, said pushrod guide having a plurality of open ended slots, each of said slotsbeing located near the end of the push rod that engages the rocker arm,the longitudinal axis of said open ended slots being transverse to thelongitudinal axis of the internal combustion engine, moldable plasticbearing means secured in each of said slots against movement, saidbearing means being apertured to receive a portion of the push rod andstabilize the push rod in a direction parallel to the longitudinal axisof the internal combustion engine, While permitting substantial movementin a direction perpendicular to the longitudinal axis of the internalcombustion engine. 7

8. An internal combustion engine comprising a cylinder head having anopening adapted to communicate with the internal combustion enginelubricant sump, a plurality of rocker arrn supports mounted upon saidcylinder head, a plurality of pivotally mounted rocker arms, each ofsaid rocker arms being supported upon a rocker arm support, each of saidrocker arms having a push rod engaging end and a poppet valve engagingend, and a plurality of laterally stable poppet valves mounted in saidcylinder head, each poppet valve having an end portion engaging thepoppet valve engaging end of the rocker arm, a plurality of push rods,each of said push rods having an end portion engaging the push rodengaging end of a rooker arm and push rod stabilizing means, said pushrod stabilizing means comprising a push rod guide mounted upon saidcylinder head, and an upstanding baffle integrally connected to the pushrod guide, said bafiie shielding the poppet valve from wetting by theinternal combustion engine lubricant, said push rod guide having aplurality of open ended slots located near the end of the push rod whichengages the rocker arm, and at least one trough the opening in thecylinder head, the longitudinal axis of said open ended slots beingtransverse to the longitudinal axis of the internal combustion engine, amoldable plastic bearing mounted in each of said slots, each of saidmoldable plastic bearings having an opening to receive a portion of thepush rod and stabilize the push rod in a direction parallel to thelongitudinal axis of the internal combustion engine, while permittingsubstantial movement in a direction perpendicular to the longitudinalaxis of the internal combustion engine.

9. An internal combustion engine comprising a rocker arm support, arocker arm pivoted upon said rocker arm support, said rocker arm havinga push rod engaging end and a poppet valve engaging end, a poppet valvehaving an end portion engaged by said poppet valve engaging end, a pushrod having an end portion engaged by said push rod engaging end, andpush rod stabilizing means, said push rod stabilizing means comprising alongitudinal slot formed in a component of said engine, molded plasticbearing means mounted in said slot for movement along the length of saidslot, said plastic bearing means being iapertured to reciprocallyreceive said push rod and stabilize the push rod in a direction normalto the length of said slot.

10. An internal combustion engine comprising a cylinder head, a rockerarm support mounted upon said cylinder head, a rocker arm pivotallymounted upon said rocker arm support, said rocker arm having a push rodengaging end and a poppet valve engaging end, a poppet valvereciprocally mounted in said cylinder head, said poppet valve having anend portion adapted to be engaged by the poppet valve engaging end ofsaid rocker arm, a push rod reciprocally supported by said engine, saidpush rod having an end portion adapted to be engaged by the push rodengaging end of said rocker arm, and push rod stabilizing means, saidpush rod stabilizing means comprising a push rod guide mounted upon saidcylinder head, an upstanding baffle integrally formed with said push rodguide for shielding the poppet valve from wetting by the lubricant ofsaid engine, said push rod guide having a longitudinal slot encirclingsaid push rod and limiting movement of said push rod in one directionwhile permitting free movement of said push rod in a direction normal tosaid one direction.

11. An internal combustion engine comprising a rocker arm supportsecured to the engine, a rocker arm pivoted upon said rocker armsupport, said rocker arm having a push rod engaging end and a poppetvalve engaging end, a poppet valve having an end portion engaged by saidpoppet valve engaging end of said rocker arm, an enlarged apertureformed in a portion of said engine, a push rod reciprocally supported insaid aperture and having an end portion engaged by said push rodengaging end of said rocker arm, a hydraulic tappet in engagement withanother end portion of said push rod, said aperture in the portion ofthe engine being sufiiciently large to permit removal of said hydraulictappet without necessitating removal of the portion of the engine, andpush rod stabilizing means extending across said aperture, said push rodstabilizing means having a longitudinal slot encircling said push rod inlimiting movement of said push rod in one direction while permittingfree movement of said push rod in another direction.

References Cited in the file of this patent UNITED STATES PATENTS718,064 White Jan. 6, 1903 1,246,343 Snadecki Nov. 13, 1917 2,963,012Kolbe Dec. 6, 1960 3,027,972 Kaecker Apr. 3, 1962

8. AN INTERNAL COMBUSTION ENGINE COMPRISING A CYLINDER HEAD HAVING ANOPENING ADAPTED TO COMMUNICATE WITH THE INTERNAL COMBUSTION ENGINELUBRICANT SUMP, A PLURALITY OF ROCKER ARM SUPPORTS MOUNTED UPON SAIDCYLINDER HEAD, A PLURALITY OF PIVOTALLY MOUNTED ROCKER ARMS, EACH OFSAID ROCKER ARMS BEING SUPPORTED UPON A ROCKER ARM SUPPORT, EACH OF SAIDROCKER ARMS HAVING A PUSH ROD ENGAGING END AND A POPPET VALVE ENGAGINGEND, AND A PLURALITY OF LATERALLY STABLE POPPET VALVES MOUNTED IN SAIDCYLINDER HEAD, EACH POPPET VALVE HAVING AN END PORTION ENGAGING THEPOPPET VALVE ENGAGING END OF THE ROCKER ARM, A PLURALITY OF PUSH RODS,EACH OF SAID PUSH RODS HAVING AN END PORTION ENGAGING THE PUSH RODENGAGING END OF A ROCKER ARM AND PUSH ROD STABILIZING MEANS, SAID PUSHROD STABILIZING MEANS COMPRISING A PUSH ROD GUIDE MOUNTED UPON SAIDCYLINDER HEAD, AND AN UPSTANDING BAFFLE INTEGRALLY CONNECTED TO THE PUSHROD GUIDE, SAID BAFFLE SHIELDING THE POPPET VALVE FROM WETTING BY THEINTERNAL COMBUSTION ENGINE LUBRICANT, SAID PUSH ROD GUIDE HAVING APLURALITY OF OPEN ENDED SLOTS LOCATED NEAR THE END OF THE PUSH ROD WHICHENGAGES THE ROCKER ARM, AND AT LEAST ONE TROUGH COMMUNICATING WITH THEOPENING IN THE CYLINDER HEAD, THE LONGITUDINAL AXIS OF SAID OPEN ENDEDSLOTS BEING TRANSVERSE TO THE LONGITUDINAL AXIS OF THE INTERNALCOMBUSTION ENGINE, A MOLDABLE PLASTIC BEARING MOUNTED IN EACH OF SAIDSLOTS, EACH OF SAID MOLDABLE PLASTIC BEARINGS HAVING AN OPENING TORECEIVE A PORTION OF THE PUSH ROD AND STABILIZE THE PUSH ROD IN ADIRECTION PARALLEL TO THE LONGITUDINAL AXIS OF THE INTERNAL COMBUSTIONENGINE, WHILE PERMITTING SUBSTANTIAL MOVEMENT IN A DIRECTIONPERPENDICULAR TO THE LONGITUDINAL AXIS OF THE INTERNAL COMBUSTIONENGINE.